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