I've dated a couple of older women and I found that it's a balance between appearing mature and "not like" other guys your age, but also expounding all the advantages of youth.
Dress well, don't crack childish jokes, don't act as if you're really aware of the age difference at all. Give the appearance that your life is together and that you're not unable to take care of yourself and looking for a Mummy substitute.
If she says things like "Aren't I a bit old for you?" You could reply with something like "No, but if you're struggling with the whole age thing I can give you a five minute time out to get your head round it

" There are numerous other replies to this common shit test however, probably better than mine.
If she says anything like, "So what do you prefer about older women?"
Reply with something like, "Well, they're mature, they have more life experience and are generally more intellectually stimulating than the younger generation. Also, you're more capable of truly appreciating my qualities, a lot of girls my age are wow'ed by nice cars and materialism which creates shallow relationships"
EDIT: Don't use the phrase "The younger generation" haha! That is not a good thing to say.
Obviously you don't have to quote that verbatim and might want to add your own spin on it, maybe about how they don't play games etc and that you feel girls your own age are perhaps not mature enough to appreciate you etc. But this is ONLY if she brings up the age thing, if not, then don't bring it up yourself.
As for the sex thing, in my opinion it depends on what vibe you're getting.
Older woman I have dated were VERY cautious and shit tested me relentlessly, because they're aware of younger guys fantasising about older women, fucking them and then going home and high fiving their buddies. Don't give this vibe at all. You need to show that you're a gentleman and not just out to get your dick wet and brag about it about how you banged a hot older woman.