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