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