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