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