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