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