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