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