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