One vertex per element, one color per generator, with an edge from x to x·s.
(2,3)(5,6,11,18,12,19,35,49,13,20,34,48,10,17,9,16)(7,14,24,40,23,39,56,65,25,41,58,67,36,50,22,38)(8,26,30,46,31,47,28,43,32,60,33,15,29,44,61,45)(21,51,53,64,27,59,52,66,54,68,55,37,57,63,62,42)(1,2,4,3)(5,7)(6,14)(8,27)(9,22)(10,36)(11,24)(12,23)(13,25)(15,42)(16,38)(17,50)(18,40)(19,39)(20,41)(21,29)(26,59)(28,55)(30,52)(31,54)(32,57)(33,62)(34,58)(35,56)(37,43)(44,51)(45,64)(46,66)(47,68)(48,67)(49,65)(53,61)(60,63)(1,3,4,2)(5,8)(6,15)(7,21)(9,33)(10,31)(11,28)(12,29)(13,32)(14,37)(16,47)(17,45)(18,26)(19,43)(20,46)(22,55)(23,57)(24,52)(25,54)(27,36)(30,35)(34,61)(38,59)(39,66)(40,51)(41,64)(42,50)(44,49)(48,60)(53,56)(58,62)(63,65)(67,68)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.