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