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