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