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