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