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