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