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