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