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