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