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