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