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