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