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