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