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