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