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