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