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