Most guys do not want an overly aggressive chick.
There is something very undignified about a woman who literally throws herself at you. It's unattractive.
If you want to convey interest, TOUCH the guy. Use your hand, touch his leg, arm, be touchy. That will greenlight. As for being more aggressive than this, you could just get your face closer. But, a lot of guys won't like it if a bitch makes the initial aggressive move. Some might, but most won't.
Wear tastefully slutty clothing. If a chick wants a guy to make a move it is all about how she ADVERTISES, not about her actually making the moves. Shorter skirts, tight shirts, etc., help convey to a guy that a ho is interested. You can guide the conversation onto your underwear; that pretty much is an invitation in not so many words.
But, if a chick just out and said "do you want to fuck," I'd probably say "no thanks, sweetie" with an air of patronization. In fact, the times I've turned chicks down for sex has been more fun than some of the sex I've had because women do NOT respond well to rejection. Some of them lapse into almost apoplexy, like those androids that get short circuited and just keep making the same movement over and over again. And, since I'm into picking up chicks for the powertrip ANYWAY, that accomplishes the goal and is incredibly entertaining. But, I think I may have drifted off topic here.