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