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