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