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