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