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