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