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)(11,21)(12,17)(13,18)(14,19)(15,20)(16,22)(23,24)(25,26)(27,32)(28,33)(29,39)(30,35)(31,36)(34,38)(37,40)(1,3)(2,4)(5,8)(6,7)(11,22)(12,23)(16,21)(17,24)(25,26)(27,37)(28,33)(29,34)(30,35)(31,36)(32,40)(38,39) involution — undirected(9,11)(10,16)(12,19)(13,23)(14,24)(15,22)(17,18)(20,21)(25,27,31,40)(26,32,36,37)(28,38,35,29)(30,39,33,34)(2,6)(4,7)(9,12,15,23)(10,17,20,24)(11,19,22,13)(14,16,18,21)(25,28)(26,33)(27,38)(29,40)(30,36)(31,35)(32,34)(37,39)(1,3)(2,4)(5,8)(6,7)(9,13,15,19)(10,18,20,14)(11,23,22,12)(16,17,21,24)(25,29,31,38)(26,34,36,39)(27,28,40,35)(30,37,33,32)(1,4)(2,3)(5,7)(6,8)(9,14,15,18)(10,19,20,13)(11,24,22,17)(12,21,23,16)(25,30,31,33)(26,35,36,28)(27,39,40,34)(29,37,38,32)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.