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