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