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