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