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