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