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