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