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