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