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