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