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