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