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