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