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