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