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