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