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