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