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)(25,26,31,34)(27,32,30,28)(29,33,38,40)(35,37,39,36)(1,2,5,6)(3,7,4,8)(9,11)(10,14)(12,19)(13,18)(15,23)(16,22)(17,20)(21,24)(25,27,31,30)(26,32,34,28)(29,35,38,39)(33,37,40,36)(1,3,5,4)(2,7,6,8)(9,12)(10,15)(11,17)(13,20)(14,21)(16,24)(18,19)(22,23)(25,28,30,26,31,32,27,34)(29,37,39,40,38,36,35,33)(1,3,5,4)(2,8,6,7)(12,20)(15,24)(17,19)(21,23)(25,29)(26,33)(27,35)(28,36)(30,39)(31,38)(32,37)(34,40)(1,4,5,3)(2,8,6,7)(10,16)(11,18)(15,24)(17,19)(26,34)(28,32)(29,38)(35,39)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.