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