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