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