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