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