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