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