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