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