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