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