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