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