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