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