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