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