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