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