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