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