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