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