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