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