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