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