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