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