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