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