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