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