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