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