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