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