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