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