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