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