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