You can download and print the PDF pattern with two different designs or download the blank flexagon and fill it in with your own designs or colors. I started with the ready-made design and then did this pattern myself.
TIP: The instructions don't specify what kind of paper to use. I used card stock at first, thinking it would be sturdier, but the edges got roughed up very quickly. I did this particular one with printer paper instead (I used premium quality). The edges on this one buckle just a bit, but it still looks new and it's easier to maneuver.