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)(11,15,19,22)(12,17,21,24)(13,20,23,18)(25,26,30,34)(27,33,37,31)(28,29,39,32)(35,40,38,36)(2,5)(3,8)(9,11)(10,15)(12,18)(13,17)(14,19)(16,22)(20,21)(23,24)(25,27,30,37)(26,31,34,33)(28,35,39,38)(29,36,32,40)(1,3)(2,6)(4,5)(7,8)(10,16)(11,19)(12,21)(13,23)(25,28,30,39)(26,32,34,29)(27,35,37,38)(31,40,33,36)(1,4,7,6)(2,3,5,8)(9,11)(10,15)(12,18)(13,17)(14,19)(16,22)(20,21)(23,24)(25,28)(26,32)(27,35)(29,34)(30,39)(31,40)(33,36)(37,38)(1,5,7,2)(3,4,8,6)(9,12)(10,17)(11,20)(13,22)(14,21)(15,23)(16,24)(18,19)(25,27)(26,33)(28,38)(29,36)(30,37)(31,34)(32,40)(35,39)(1,6,7,4)(2,8,5,3)(9,13,14,23)(10,18,16,20)(11,17,19,24)(12,22,21,15)(25,29,30,32)(26,28,34,39)(27,36,37,40)(31,35,33,38)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.