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