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