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