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