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