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