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