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