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)(12,21)(13,18)(14,22)(15,17)(16,20)(23,24)(25,26,30,33)(27,29,35,31)(28,36,37,32)(34,38,40,39)(2,3)(6,7)(9,11,15,20)(10,16,17,19)(12,13,22,23)(14,18,21,24)(25,27,30,35)(26,31,33,29)(28,34,37,40)(32,38,36,39)(1,3,5,2)(4,7,8,6)(10,17)(11,20)(12,22)(18,24)(28,37)(32,36)(34,40)(38,39)(1,4)(2,6)(3,7)(5,8)(9,12)(10,14)(11,13)(15,22)(16,18)(17,21)(19,24)(20,23)(25,28)(26,32)(27,34)(29,39)(30,37)(31,38)(33,36)(35,40) involution — undirected(9,13)(10,18)(11,12)(14,16)(15,23)(17,24)(19,21)(20,22)(25,29)(26,27)(28,38)(30,31)(32,40)(33,35)(34,36)(37,39) involution — undirected(9,14)(10,12)(11,18)(13,16)(15,21)(17,22)(19,23)(20,24)(25,27)(26,29)(28,34)(30,35)(31,33)(32,39)(36,38)(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.