One vertex per element, one color per generator, with an edge from x to x·s.
(1,2) involution — undirected(4,8)(5,6)(9,10)(11,12,15,21,17,22,30,20,16,19,31,36,29,37,14,28)(13,23,25,33,27,38,41,40,26,39,42,18,32,34,24,35)(3,4)(5,8)(6,10)(7,9)(11,13,16,26)(12,18,19,33)(14,25,30,42)(15,24,31,41)(17,32,29,27)(20,38,28,34)(21,39,36,23)(22,40,37,35)(3,5,7,6)(4,8,9,10)(12,19)(18,33)(20,28)(21,36)(22,37)(23,39)(34,38)(35,40)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.