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