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