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