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