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