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