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