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