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