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