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