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