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