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