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