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