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