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