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