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