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