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