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