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