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