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