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