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