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