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