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