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