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