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