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