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