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