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