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