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