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