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