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