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