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)(25,26,29,35,30,32,31,36)(27,37,40,33,34,39,38,28)(2,6)(3,4)(9,11,14,21)(10,15,18,19)(12,20,13,22)(16,23,17,24)(26,32)(27,34)(35,36)(38,40)(1,2)(3,8)(4,7)(5,6)(9,12,14,13)(10,16,18,17)(11,20,21,22)(15,23,19,24)(25,27)(26,33)(28,32)(29,38)(30,34)(31,40)(35,37)(36,39)(1,3,5,4)(2,7,6,8)(9,13,14,12)(10,17,18,16)(11,20,21,22)(15,23,19,24)(25,28,30,33)(26,34,32,27)(29,37,31,39)(35,38,36,40)(1,4,5,3)(2,7,6,8)(10,18)(15,19)(16,17)(23,24)(25,29,30,31)(26,35,32,36)(27,38,34,40)(28,39,33,37)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.