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