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