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