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