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