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