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