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