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