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