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