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