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