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)(14,16)(17,18,20,22)(19,21,24,23)(25,26,30,28)(27,33,34,31)(29,36,37,32)(35,38,40,39)(1,3)(2,6)(4,7)(5,8)(9,10,13,12)(11,14,15,16)(17,18)(19,21)(20,22)(23,24)(27,34)(29,37)(31,33)(32,36)(3,8)(6,7)(11,15)(14,16)(17,18,20,22)(19,21,24,23)(25,27,30,34)(26,31,28,33)(29,35,37,40)(32,38,36,39)(1,3)(2,7)(4,6)(5,8)(9,11)(10,14)(12,16)(13,15)(17,18)(19,23)(20,22)(21,24)(25,28,30,26)(27,31,34,33)(29,36,37,32)(35,38,40,39)(1,4,5,2)(3,7,8,6)(9,12,13,10)(11,14,15,16)(17,19,20,24)(18,21,22,23)(25,29,30,37)(26,32,28,36)(27,35,34,40)(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.