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