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