I think the best way to write from his perspective would be to emphasize the way what he means is quite different from the way people perceive him, so as to show that his 'bad boy' nature is, in fact, a misconception of his character.
There are a few ways of doing this:
Implied through action:
Confident people tend to take the lead without
really thinking.
For example: say he's part of a group eating dinner
and he instantly sits at the head of the table. This could be totally
subconscious, but others see it as him being 'full of himself' because
'he didn't even ask!'
Another example might be him deciding which restaurant to go to by himself because he feels like Chinese food, without realizing that one of the people in the group is allergic/doesn't like Chinese, making him seem inconsiderate.
Part of the way confidence can be misconstrued
as arrogance is due to the way confident people are used to taking the
lead and doing what they want - the assumption being, that if someone
else wanted it, they'd have done it first or speak up - without
realizing that introverts/timid people would have a very hard time
doing it, and might just label the confident person as selfish for not asking.
Then there's option two:
Implied through dialogue:
Confident people tend to speak in a manner that leaves less room for being contradicted or denied.
Asking leading questions that imply you've already said yes to a different topic is a very confident manner of speaking - it makes it seem like the speaker doesn't believe for a second there was a chance of the word 'no' (and maybe he really does believe that!)
Note that this is a common pickup artist tactic, which I think is an excellent topic of research when trying to write confident characters - their mannerisms might be especially helpful with writing a convincing playboy.
Example: "Hey, Jessica, what's better for you - Saturday or Sunday?" Will asked, tapping her on the shoulder to get her attention.
Jessica turned around. "Saturday... um, for what?"
"Our date." Will grinned.
Another way of showing this is saying questions as statements, like flipping money at someone and saying 'get me a mocha latte.' - this could be a carried over from being a business man used to ordering around his secretary.
Even more ideas - apologizing can be seen as weak, especially if done too often, and so your character subconsciously avoids it by opting for other phrases - instead of "Sorry I'm late." he might say "Thanks for waiting."
and lastly:
Implied through thought:
Confident people tend to think in a way where failure isn't an option.
Instead of thinking Will Jessica say yes if I ask her out? he might
think I should take Jessica to [insert restaurant here] on our date.
as though she already said yes.
Or if there's rumors of a promotion in his company, he might think I
hope my new office has windows. because he just assumes he'll be
chosen due to being more competent than his co-workers.
That being said, having him be utterly unshakable would get boring
quick - you should still have a couple moments/things in the story
which make him crumple - lets say he can't stand up to his mother for the
life of him, and docilely does everything she says even if he hates
it, or say, he gets really shaken when he discovers that one of his
girlfriends cheated on him for once, or the promotion went to
someone who he thought he was better than in every way, ect. ect.
Moments of weakness is what makes even the strongest characters seem
human!
One last additional thought - confidence is a virtue people love, and a over-confidence (and womanizing) is a pretty likable flaw in fiction - it seems unlikely to me that the readers might see him as an antagonist.
