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