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