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