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