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