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