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