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