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