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