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