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