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