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