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