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