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