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