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