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