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