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