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