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