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