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