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