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