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