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