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