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