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