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