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