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