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)(11,14)(12,15)(13,16)(17,21)(18,22)(19,23)(20,24)(25,26,31,35)(27,36,34,30)(28,32,38,40)(29,33,39,37)(9,11)(10,14)(12,19)(13,17)(15,23)(16,21)(18,20)(22,24)(25,27,30,26,31,34,36,35)(28,37,39,32,38,33,29,40)(1,3,5,4)(2,6,7,8)(11,17)(14,21)(18,19)(22,23)(25,28)(26,32)(27,37)(29,36)(30,39)(31,38)(33,34)(35,40)(9,12,13,20)(10,15,16,24)(11,18,17,19)(14,22,21,23)(25,29,31,39)(26,33,35,37)(27,32,34,40)(28,36,38,30)(1,4,5,3)(2,6,7,8)(10,16)(14,21)(15,24)(22,23)(28,38)(29,39)(32,40)(33,37)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.