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