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