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