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