More of a WAG, but “hit” is used in a lot of slang, specifically things that I think might be related are “to hit on [someone]”, or “to hit [drugs/cigarettes]”. My guess is it evolved from one of these two. As in, I could see someone saying “What do you think of that?” “Man, I’d like to hit on that!” implying that he’d hit on her just to get laid. I’d then imagine the “on” just got dropped.
Or, other directly related phrases are “I’d tap that”, “I’d bang her”, “I’d boink her”, etc. all of these words are very close to “hit”, so it could just be a natural progression to use a word that’s related in other senses to have the same meaning in this one. Of course, I have no idea which set came first.