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