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