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