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