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