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