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