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