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