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