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