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