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