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