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