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