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