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