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