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