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