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