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