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