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