Originally Posted by RoadGuy

I would not leave the chain like that if I were you. From the photo, I can see that you have a Trek carbon bike. Carbon parts and chains do not play nice. The chain sagging, slapping, rubbing, or tapping, on the carbon chainstay may cause damage that can eventually ruin the frame.

I would not ride the bike that way. Do whatever it take to prevent contact between the carbon chainstay and and the chain. Some solutions that have been already mentioned: bigger small cog on cassette, or shortening the chain, or replacing the rear deralleur with one with more capacity (longer cage).