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