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