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)(11,17)(12,21)(13,24)(14,18)(15,16)(19,23)(20,22)(28,36)(32,37)(34,40)(38,39)(3,7)(5,8)(10,16)(13,18)(17,21)(19,22)(25,26)(27,31)(28,37)(29,33)(30,35)(32,36)(34,38)(39,40) involution — undirected(1,2)(3,5)(4,6)(7,8)(9,11,15,12)(10,17,16,21)(13,19,18,22)(14,20,24,23)(25,27)(26,30)(28,34)(29,35)(31,33)(32,38)(36,40)(37,39)(1,3,4,7)(2,5,6,8)(9,12,15,11)(10,17,16,21)(13,22,18,19)(14,20,24,23)(25,27)(26,31)(28,34)(29,35)(30,33)(32,39)(36,40)(37,38)(1,2)(3,5)(4,6)(7,8)(9,13,15,18)(10,14,16,24)(11,19,12,22)(17,20,21,23)(25,28)(26,32)(27,34)(29,36)(30,38)(31,39)(33,37)(35,40)(9,14)(10,18)(11,20)(12,23)(13,16)(15,24)(17,22)(19,21)(25,26)(27,30)(28,32)(29,33)(31,35)(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.