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