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