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