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