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