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