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