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