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