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