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