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