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