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