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)(15,18)(19,23)(22,24)(25,26)(27,34)(28,32)(29,33)(30,35)(31,37)(36,40)(38,39) involution — undirected(1,3,5,8)(2,4,6,7)(9,10)(11,18)(12,16)(13,14)(15,17)(19,24)(20,21)(22,23)(25,27)(26,31)(28,36)(29,38)(30,37)(32,39)(33,40)(34,35)(2,6)(3,8)(10,14)(15,18)(16,20)(22,24)(25,28,30,29)(26,32,35,33)(27,36,37,38)(31,39,34,40)(1,3)(2,7)(4,6)(5,8)(9,11)(10,15)(12,19)(13,17)(14,18)(16,22)(20,24)(21,23)(25,29,30,28)(26,33,35,32)(27,36,37,38)(31,39,34,40)(1,3)(2,4)(5,8)(6,7)(9,10)(11,15)(12,20)(13,14)(16,21)(17,18)(19,24)(22,23)(25,27)(26,34)(28,38)(29,36)(30,37)(31,35)(32,39)(33,40) involution — undirected(1,4)(2,8)(3,6)(5,7)(9,12)(10,16)(11,19)(13,21)(14,20)(15,22)(17,23)(18,24)(25,26)(27,31)(28,32)(29,33)(30,35)(34,37)(36,39)(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.