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