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