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