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