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