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