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