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