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