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