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