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