One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,6)(4,5)(7,8)(9,10,12,14)(11,15,16,13)(17,18,21,27)(19,26,22,23)(20,30,31,24)(25,28,32,29)(2,5)(6,8)(17,19,21,22)(18,23,27,26)(20,29,31,28)(24,25,30,32)(9,11,12,16)(10,13,14,15)(17,20)(18,24)(19,28)(21,31)(22,29)(23,32)(25,26)(27,30)(17,20)(18,25)(19,29)(21,31)(22,28)(23,30)(24,26)(27,32) involution — undirected(1,3,4,7)(2,6,5,8)(17,19,21,22)(18,26,27,23)(20,29,31,28)(24,32,30,25)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.