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