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