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