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)(19,28)(20,30)(21,26)(22,27)(23,29)(24,25)(31,32) involution — undirected(2,5)(6,8)(9,11,12,15)(10,13,14,16)(17,19,21,30,22,25,23,31)(18,24,26,32,27,28,29,20)(3,7)(6,8)(17,20,23,24,22,32,21,28)(18,25,26,30,27,19,29,31)(1,3,4,7)(2,6,5,8)(10,14)(13,16)(17,21,22,23)(18,26,27,29)(19,30,25,31)(20,24,32,28)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.