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