One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,11)(4,8)(5,9)(6,10)(7,13)(12,16)(14,15)(17,18)(19,27)(20,26)(21,25)(22,24)(23,28)(29,31)(30,32)(33,34,37,41,38,42,48,54)(35,39,45,51,44,50,57,61)(36,40,47,53,46,52,58,62)(43,49,56,60,55,59,63,64)(1,3)(2,7)(4,12)(5,14)(6,13)(8,15)(9,16)(10,11)(17,19)(18,23)(20,30)(21,29)(22,28)(24,27)(25,32)(26,31)(33,35)(34,39)(36,43)(37,45)(38,44)(40,49)(41,51)(42,50)(46,55)(47,56)(48,57)(52,59)(53,60)(54,61)(58,63)(62,64) involution — undirected(1,4,6,5)(2,8,10,9)(3,12,13,14)(7,15,11,16)(18,24)(19,28)(25,26)(29,30)(33,36)(34,40)(35,43)(37,47)(38,46)(39,49)(41,53)(42,52)(44,55)(45,56)(48,58)(50,59)(51,60)(54,62)(57,63)(61,64)(1,5,6,4)(2,9,10,8)(3,12,13,14)(7,15,11,16)(17,20,22,21)(18,25,24,26)(19,29,28,30)(23,31,27,32)(35,44)(36,46)(39,50)(40,52)(45,57)(47,58)(51,61)(53,62)(2,10)(7,11)(8,9)(15,16)(17,21,22,20)(18,26,24,25)(19,29,28,30)(23,31,27,32)(35,44)(39,50)(43,55)(45,57)(49,59)(51,61)(56,63)(60,64)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.