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)(17,18)(19,27)(20,25)(21,26)(22,31)(23,30)(24,29)(28,32)(1,3,5,8)(2,6,4,7)(11,15)(13,16)(17,19)(18,23)(20,28)(21,30)(22,29)(24,25)(26,27)(31,32)(2,4)(6,7)(9,11)(10,13)(12,15)(14,16)(17,19)(18,24)(20,29)(21,30)(22,28)(23,25)(26,32)(27,31) involution — undirected(1,4,5,2)(3,7,8,6)(10,14)(11,15)(17,20,21,22)(18,25,26,31)(19,28,30,29)(23,24,27,32)(17,20,21,22)(18,25,26,31)(19,29,30,28)(23,32,27,24)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.