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