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