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