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