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