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