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