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