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