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