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