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