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