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