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)(27,30)(28,37)(29,32)(31,34)(33,36)(35,39)(38,40)(1,2)(3,5)(4,6)(7,8)(10,16)(13,17)(18,22)(21,24)(25,27)(26,30)(28,38)(29,35)(31,36)(32,39)(33,34)(37,40) involution — undirected(1,2,4,6)(3,7,8,5)(9,11,15,12)(10,17,16,13)(14,20,23,19)(18,21,22,24)(25,28,31,29)(26,32,34,37)(27,35,36,38)(30,40,33,39)(3,8)(5,7)(9,12,15,11)(10,13,16,17)(14,20,23,19)(18,21,22,24)(25,29,31,28)(26,32,34,37)(27,35,36,38)(30,39,33,40)(1,3)(2,5)(4,8)(6,7)(9,13)(10,12)(11,16)(14,21)(15,17)(18,20)(19,22)(23,24)(25,30,31,33)(26,27,34,36)(28,39,29,40)(32,38,37,35)(1,2)(3,5)(4,6)(7,8)(9,14,15,23)(10,18,16,22)(11,19,12,20)(13,21,17,24)(25,27)(26,33)(28,38)(29,35)(30,34)(31,36)(32,40)(37,39)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.