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