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