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