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