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