I use a sling called a "Bow Buddy" sling. It is just the style that has loops that go around the cams. I can slip the loop off the top cam of the bow and then rotate the bow to get the bottom loop to come off without touching it. It has a wide range of adjustability for different length bows, I have only used it with bows from 30" to 33" myself though.
It also allows the strap to be adjusted so the bow sits where you want it height wise on your body.
It is a guy local to me that makes them, I bought mine about 5 years ago from him when he was set up at a local 3d shoot.
The guy has a FB page for selling them too I think, it should come up by just searching "bow buddy bow slings".
As far as a covering the string and cam style. I've never damaged a cam or string while hunting but I am pretty vigilant in watching for grass, twigs, or weeds getting trapped between the string and cam. I worry about that derailing the string when drawing more than anything else.