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