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