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