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