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