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