So, perhaps you are smaller than the average human, but you have above average standards when it comes to looking good and avoiding dangling straps on your travel gear. This will show you a few ways to fix up your pack to make it look the best.
First, of course you can adjust your strap with the pull strap that has the lovely strap management piece on the end. Here it is pulled completely as short as possible.
You can then roll up that loop and secure it with a somewhat temporary holder- a rubber band (using brown here for visual clarity) I'd suggest using black or a color you love. Check out this simple product for a great re-usable solution for straps and other cords in all sorts of colors! Cord Organizers in 6 colors.
You can also unhook the strap with the bottom clasp and wrap the rubber band around the folded loop AND the back strap, to have it lay a bit smoother:
Alternatively, you can *commit* to the length you want and cut the strap. Remember that if you cut it, that will limit your ability to change the strap length later... or allow other people to use it who might be a different size. Most users find that they find the right length and then never adjust again. If you are one of those, maybe be bold and cut it.
After cutting as clean and straight a line as you can, melt the ends of the webbing so it doesn't fray.