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