One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,6)(4,5)(7,8)(9,10)(11,13)(12,14)(15,16)(17,18)(19,20)(21,31)(22,26)(23,25)(24,29)(27,32)(28,30) involution — undirected(2,5)(6,8)(9,11,12,15)(10,13,14,16)(17,18,22,26)(19,27,29,30)(20,28,24,32)(21,25,23,31)(10,14)(13,16)(17,19,22,29)(18,24,26,20)(21,28,23,32)(25,30,31,27)(17,20,22,24)(18,19,26,29)(21,30,23,27)(25,32,31,28)(1,3,4,7)(2,6,5,8)(17,21,22,23)(18,25,26,31)(19,28,29,32)(20,27,24,30)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.