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