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