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