Using the provided packed dimensions, the volume is 1.38 L = 84 in^3 = 11 in * (5.5/2 in)^2. So a stuff sack that's at least 11" long with a total volume of at least 1.4 L should work for this.
I just tie a bit of cord around it. It's squished into the bottom of my pack anyway so it doesn't unroll.
Sorry, forgot the pi...should be 4.3 L!