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